1. Field of the Invention
The present invention relates to a spine fixation apparatus, and more particularly to a pedicle screw implanted into a spine and an operating device for the pedicle screw capable of easily inserting a rod to a head section of the pedicle screw in order to securely fix the spine.
2. Description of the Prior Art
As generally known in the art, a spine fixation apparatus is provided for treating patients who have vertebral disease caused by traffic accidents or fall accidents. For instance, the spine fixation apparatus connects bones forming the spine to each other so as to assist patients with vertebral fracture to be restored to health.
A patient makes a living with a spine fixation apparatus implanted into the spine of the patient. Thus, a subsidiary implanted into a body of the patient must have a simple structure and must not be deformed or released even if the patient takes an active life for a long period of time.
FIG. 1 shows a conventional spine fixation apparatus. Referring to FIG. 1, the conventional spine fixation apparatus includes a pedicle screw 100 provided with a rod 104 and a coupling screw 102 which are coupled to an upper portion of the pedicle screw 100.
The pedicle screw 100 is provided at an upper end thereof with a head section 110 and a lower end thereof with a screw section 120. The rod 104 is inserted into a recess 114 of the head section 110. The recess 114 is defined by first and second sidewalls 111 and 112 and receives the rod 104 therein.
When the rod 104 has been received in the head section 110 of the pedicle screw 100, the coupling screw 102 is screw-coupled into the upper portion of the pedicle screw 100 so as to prevent the rod 104 from being separated from the pedicle screw 100. The first and second sidewalls 111 and 112 of the head section 110 are formed at inner portions thereof with screw sections such that the coupling screw 102 is securely fixed to the head section 110 of the pedicle screw 100.
The screw section 120 of the pedicle screw 100 is screw-coupled into a bone of a spine of a patient so that the pedicle screw 100 is implanted into a body of the patient. The pedicle screw 100 is connected to the other pedicle screw, which is screw-coupled with the other bone of the spine of the patient, through the rod 104.
The rod 104 is inserted into the pedicle screw 100 from an upper portion of the pedicle screw 100 when the pedicle screw 100 is implanted into the patient. Accordingly, it is necessary to make elongated incisions in the patient's back. That is, the back of the patient must be incised corresponding to a length of the rod 104. Reference numeral 116 represents an inner bottom surface of the head section 110.
The current tendency of a surgical operation is to minimize an incision part in a human body. Thus, there has been suggested a method capable of minimizing an incision part in the back of a patient when a pedicle screw is implanted into the body of the patient. According to the above method, a rod is inserted into the pedicle screw from a lateral portion of the pedicle screw instead of inserting the rod from an upper portion of the pedicle screw. In this case, two pedicle screws can be implanted into the body of the patient without incising the back of the patient in a long size by forming only three incisions (two is for pedicle screws and one is for the rod) in the back of the patient.
When the rod is inserted into the pedicle screw from the lateral portion of the pedicle screw, one end of the rod must be easily inserted into a recess part of the pedicle screw. In addition, it is necessary to prevent the rod from being easily separated from the recess part. The rod is inserted into the recess part of a head section of the pedicle screw and fixedly coupled thereto by means of a coupling screw. Accordingly, the rod can be easily separated from the head section of the pedicle screw before the coupling screw is coupled thereto.
For this reason, if the conventional pedicle screw is used for the minimum incision surgery, the pedicle screw may be separated from the pedicle screw while the surgery operation is being carried out, resulting a delay or a failure of the surgery operation.
In addition, since the minimum incision surgery is carried out while making several incisions in the back of the patient while keeping the size of the incisions quite small, a position of the pedicle screw is not exposed to an exterior. Thus, it is difficult to determine a coupling position of a screw section of the pedicle screw having a diameter of about 5 mm with respect to the spine of the patient.
In the meantime, the minimum incision surgery requires great skill when determining the coupling position of the pedicle screw with regard to the spine of the patient and inserting the rod into the pedicle screw from the lateral portion of the pedicle screw. This is because the incisions made in the back of the patient tend to be clogged by skin and the operator cannot see the pedicle screw, which has already been implanted in the body of the patient. Thus, the operator must perform the surgical operation while gripping the pedicle screw with one hand in order to couple the pedicle screw to a precise position of the spine of the patient.
That is, since the minimum incision surgery is carried out while making several incisions in the back of the patient and keeping the size of the incisions quite small, the location of the pedicle screw is “subcutaneous”, so that the operator cannot easily carry out minimum incision surgery.
Therefore, it is necessary to provide an apparatus to facilitate minimum incision surgery capable of allowing the operator to easily couple a pedicle screw to the spine of the patient and insert a rod into the pedicle screw from a lateral portion of the pedicle screw.